Multifrequency impedance testing in relation to otospongiotic stapedial fixation and other factors

After reviewing COLLETTI'S research, the authors describe their own experimental work on multifrequency impedance testing in relation to stapedial fixation in otospongiosis, and other factors. Their findings, based on 266 tested ears, lead the authors to the conclusion that : (1) the most useful frequencies, from the clinical point of view, are the low ones (220, 660 and 800 Hz); (2) the research frequencies, range beyond (900 to 2 000 Hz), for a finer diagnosis, but are confused by numerous artefacts and are not always reliable; (3) COLLETTI'S conclusions on the inversion of the peak and on the shifting of M and W, are valuable, but not always reliable in some cases.